Method for the utilization of energy from cyclic thermochemical processes to produce mechanical energy and plant for this purpose

ABSTRACT

There is described a method for operation of a traditional engine or turbine, where instead of a combustion reactor there are utilized cyclic thermochemical processes that drive the engine or turbine without the formation of waste gases that are harmful to the environment.

The present invention relates to the utilization of energy from cyclicthermochemical processes in common motors and turbines, and to specificprocesses for use in motors and/or turbines under various exteriorconditions. More specifically the invention relates to a method forproduction of mechanical energy from an energy producing unit such as aturbine, rotor piston engine and piston engine or the like, comprisingfeeding an input fluid to the energy producing unit, where the inputfluid before entering or within the unit undergoes a thermochemicalreaction and/or phase change causing a volume expansion of the fluid,which volume expansion drives the energy producing unit.

Cyclic thermochemical processes are used today in the chemicalprocessing industry, inter alia in adsorption-desorption, in theproduction of hydrogen (see McAuliffe Ch. A. “Hydrogen and energy” L.1980) and in biochemistry in the ornithine cycle and the like. Energyand products from these processes are not used, however, as actuatingfluid in energy producing equipment such as turbines and rotor andpiston engines.

Until now turbines and rotor and piston engines have often been used inor in connection with combustion engines, where the actuating fluidconsists of hydrocarbons. The hydrocarbons undergo an oxidation processthat develops heat and/or produces a volume increase. On combustionthere are formed waste gases, which constitute an environmental problem.

For combustion engines various apparatuses and methods are known for therecycling of portions of the waste gases from the combustion process.Such methods are described, inter alia, in EP 340545, U.S. Pat. No.5,016,599, U.S. Pat. No. 3,677,239, U.S. Pat. No. 3,712,281 and U.S.Pat. No. 4,587,807. These processes use traditional actuating fluidsthat go through a course of combustion in the engines.

The purpose of the present invention is to utilize cyclic thermochemicalprocesses and phase changes in common combustion engines or turbines sothat these can be driven without a combustion process taking place andwith associated recycling/regeneration of the actuating fluid so as toavoid the formation of waste gases harmful to the environment.

A further objective of the invention is to utilize concrete actuatingfluids in cyclic thermochemical processes in turbines and/or engines.

The present invention provides a method for operation of a unit thatproduces mechanical energy such as a turbine, rotor piston engine andpiston engine, or the like. The invention is distinguished by thecharacteristic features cited in claim 1, 12-14 and 16. Further theinvention provides a plant for performing the method according to theinvention.

Additional features pertaining to preferred embodiment forms of theinvention are described in the dependent claims.

Some possible embodiment forms of the invention are shown on theaccompanying figures, where

FIG. 1 illustrates the underlying principle of the invention,

FIG. 2 shows an embodiment form with water as the actuating fluid,

FIG. 3 illustrates the principle of a gas hydrate plant,

FIG. 4 shows an embodiment form with hydrogen peroxide as actuatingfluid, and

FIG. 5 shows an embodiment form with carbon monoxide and hydrogen asactuating fluid.

FIG. 1 illustrates the fundamental principle of the invention.Mechanical energy 60 is generated in a piston engine/turbine 10 byfeeding a stream 40 of actuating fluid into it from a chemical reactor20, where a dissociation process or other chemical reaction takes placewhich results in a direct and/or an indirect volume increase. Byindirect volume increase is meant a volume increase that is due to heatgeneration as a result of an exothermic reaction. The outlet stream 30from the piston engine/turbine 10 is fed back to the chemical reactor20, where it is regenerated by means of external energy sourcesubstances 50. The invention does not include common combustionreactions, since what are involved here are cyclical thermochemicalprocesses where the actuating fluid that is fed into the engine/turbineis regenerated.

Power plants that are based on the method according to the invention andother types of power sources may be structurally combined intointegrated energy units. The type of such power sources will depend onthe natural and industrial resources that are available.

The basic idea of the invention is a technology for utilizing energyand/or the dissociation products from various compounds, obtained as aresult of a cyclic thermochemical process or phase change, for enginework, whereby the compounds and their dissociation products, whichconstitute at least a portion of the actuating fluid that is fed to theengine 10, after having carried out their work, undergo a total orpartial conversion or regeneration to the compounds initially usedwithout releasing waste gases into the environment.

A great number of different substances can be used as actuating fluid inthe method according to the invention, for example, water, aqueoussolutions of various compounds including gases and other low-boilingfluids, clathrates and also cold embedded compounds (including metalhydrides [for example, MgH₂] and gas hydrates of various gases or gasmixtures), hydrogen peroxide, hydrogen, hydrocarbon and carbonaceousgases capable of conversion (for example, steam and steam-oxygenconversion of methane, ethylene, acetylene, CO, CO₂, etc.). There areseveral thousand such substances known. Some typical reactions by whichthe method can be realized are shown below. CO + 3H₂

CH₄ + H₂O C₂H₄ + H₂

C₂H₆ CO₂ + 4H₂

CH₄ + 2H₂O C₁₀H₈ + 5H₂

C₁₀H₁₈ CO₂ + H₂

CO + H₂O —CH₂— + H₂O

CO + 2H₂ CO + H₂

½CH₄ + ½CO₂ C₂H₄ + HCl

C₂H₅Cl CO + H₂O

CO₂ + H₂ CO + Cl

COCl 2CO + 2H₂

CH₄ + CO₂ —CH₂— + ½O₂

CO + H₂ CH₄ + 2O₂

CO₂ + 2H₂O SO₃ + H₂O

H₂SO₄ CH₄ + ½O₂

CO + 2H₂ H₂O + H₂SO₄

H₂SO₄.H₂O CH₄ + O₂

CO₂ + 2H₂

To carry out the method according to the invention a number of differentgas hydrates may be used, as mentioned above. In Table 1 are shown anumber of hydrate-forming substances and some of the physical propertiesof the hydrates obtained. In this context the chemical breakdown isreferred to as decomposition. TABLE 1 Formation energy, decompositiontemperatures and decomposition pressures for some gas hydrates HydrateBoiling Formation Decomposition Decomposition Hydrate point StructuralMole quantity H₂O energy, temperature pressure former ° C. typeEstimated Obtained kJ/mole at 1 atm, ° C. at 0° C., MPa Ar −186 Type I 5¾ ˜6 55.4 −42.8 10.5 CH₄ −164 Type I  5¾ ˜6 60.7 −29.0 2.6 Kr −153Type I  5¾ 5.7 58.2 −27.8 1.45 CF₄ −128 Type I  5¾ — — — — Xe −107 TypeI  5¾ ˜6 69.9 −3.4 0.15 C₂H₄ −104 Type I  5¾ ˜6 64.0 −13.4 0.55 N₂O −89Type I  5¾ ˜6 62.0 −19.3 1.0 C₂H₆ −88 Type I  5¾ 5.8 ± 0.5 62.8 −15.80.52 PH₃ −87 Type I  5¾ 5.9 68.7 −6.4 0.16 C₂H₂ −84 Type I  5¾ 5.7 63.6−15.4 0.57 CO₂ −79 Type I  5¾ ˜6 61.1 −24.0 1.23 CH₃F −78 Type I  5¾ ˜6— — 0.23 H₂S −61 Type I  5¾ 5.7 68.2 +0.35 0.10 AsH₃ −55 Type I  5¾ — —+1.8 0.08 C₃H₈ −45 Type I  5¾ — — 0.0 0.10 H₂Se −42 Type I  5¾ 5.9 70.3+8.0 0.05 Cl₂ −34 Type I  5¾ 5.9 ± 0.3 67.8 +9.6 0.03 C₂H₅F −32 Type I 5¾ ˜6 84.1 +3.7 0.07 CH₃Cl −24 Type I  5¾ ˜6 75.8 +7.5 0.04 SO₂ −10Type I  5¾ 6.1 + 0.6 69.5 +7.0 0.04 CH₃Br +4 Type I  7⅔ ˜8 81.6 +11.10.02 ClO₂ +10 Type I  7⅔ ˜8 — +15.0 0.02 C₂H₅Cl +13 Type II 17 ˜16 113.6— 0.03 C₂H₅Br +38 Type II 17 — — — 0.02 CH₂Cl₂ +42 Type II 17 — 121.4 —0.02 CH₃I +43 Type II 17 17 131.5 — 0.01 CH₃CHCl₂ +57 Type II 17 — — —0.01 Br₂ +59 Type I  7⅔ 7.9 ± 0.5 82.1 — 0.01 CHCl₃ +61 Type II 17 —125.6 — 0.01

Formation energy refers to the reaction of 1 mole of gaseoushydrate-forming substance with liquid water at a temperature of 0° C.

The following examples are intended to illustrate the invention morefully without limiting it. The examples show the use of various types ofthermochemical actuating fluids and possible conditions that enhancetheir applicability.

EXAMPLE 1

Finely-Divided Water

This method may be used in steam and gas turbines, piston engines orrotor-piston engines. There are many different constructional solutionsfor their design, for example: adiabatic or diesel engines, reactiveturbines (Segner's wheel), turbines constructed for radial-flow andmixed-flow, rotor engines and Sterling engines.

The operation of power source 10 is illustrated schematically in FIG. 2.Water (fuel) from a water tank 22 is conducted through a pipeline 42into an activator 23, in this embodiment form a high pressurepump/electromagnetic dissociation device. The activated andfinely-dispersed water that is obtained is conducted through line 43 andsprayed through one or more nozzles 11 into the engine/turbine 10. Inthe illustrated version the energy producing unit is shown—forexample—as a piston engine. When the water comes into contact with aheated surface inside the engine or is brought into contact with hotcompressed gas, the water is immediately converted to steam or asteam-gas mixture. The volume of the steam or steam-gas mixture willexceed the volume of the activated and finely-dispersed water by amagnitude of 1.3·10³-9·10³ times. This volume increase will drive thepistons. When the pistons descend, the inlet ports or valves are openedand the steam or steam-gas mixture is conducted through line 30 into acondenser 21 formed as an expansion chamber. Here the pressure decreasessharply and the steam is condensed into fluid. The fluid is passedthrough line 41 back to the water tank 22. Between condenser 12 andwater tank 22 there may optionally be provided a separator, whichensures that the water conducted back to the tank 22 has the properpurity.

Up to 10% of the energy released through the process is used in thepiston engine and to activate and disperse the water. This depends onthe dissociation method. Partial dissociation allows to vary widely theprocess parameters and engines energy capacity. The water is activatedduring the process of non-equilibrium dissociation, and the followingcompounds, inter alia, are formed: H₂, H, H⁺, H⁻, HO₂ ⁺, OH, OH⁺, OH⁻,O, O₂, O⁺, O⁻, O₂ ⁺, H₂O. The quantity and the composition of the formedcompounds is completely dependent on the type of the activators used andthe parameters of the water dissociation method. During full waterdissociation the following compounds are formed:H₂O→0.1666O⁺+0.1666O⁻+0.0002H₂30 0.0001OH⁺++0.0001OH⁻+0.3332H⁺+0.3332H⁻

Accordingly, in this context, by activation is meant a chemicalactivation of the actuating fluid, whereby a portion of the actuatingfluid molecule is rendered more reactive.

The energy of the process is the sum of the steam expansion energy andthe chemical energy of the activated compounds:E=E _(w) +E _(h) +E _(d)wherein

-   E represents the energy of the process (steam expansion, activated    compounds).-   E_(w) represents the energy provided by the motor,-   E_(h) represents the energy used for heating and activating,-   E_(d) represents the energy used for dispersion.

It is assumed that E_(h)+E_(d)≈0.1E.

Further. E is equal to the sum of the individual compounds. For 1 kg ofactivated and dispersed water, therefore, E has the following magnitude:E=E _(O+) +E _(O−) +E _(H2) +E _(OH+) +E _(OH−) +E _(H+) +E _(H−)E=(0.1666×16.0×98114+0.1666×16×6344+0.0002×2.1588×143000+0.0001×17.0794×85943.6+0.0001×17.0794×492.8+1.0794×0.3332×680236+1.0794×0.3332×282801.3)/6.007=129380kJ/kg

The values are given by V. S. Stepanov (Chemical energy and exergy ofsubstances, Novosibirsk, Nauka, 1990, page 163ff).

If one further takes into account ill the calculations that the energyloss will be 1%, the specific consumption comes to 0.38 g water for 1kWh, with the rest of the water being recycled. The efficiency of theprocess depends on the type of engine that is used.

According to experimental results, the specific consumption variesbetween 0.4 and 2.0 g of water for 1 kWh. Various implementationtechnologies are found which have the capability of realizing of thepossibility of using water in power plants.

Other finely-dispersed activated fluids can be used in a similar manneras water in Example 1. Such other fluids are, for example, aqueoussolutions of gases or fluids. The volume expansion and the energy usedto activate and disperse the fluid and the energy consumed by theengine/turbine depend on the actuating fluid that is selected.

EXAMPLE 2

Use of Gas Energy Obtained by Dissociation of Clathrates, Gas Hydratesand Metal Hydrides

To attain the greatest possible yield by this embodiment form, the powersource should be situated in the proximity of a heat source 51 and acooling source 50. A heat source 51 may be, for example, waste heat fromexhaust gases, waste water from industry or other power plants, thermalsources or heating by renewable energy such as solar and wind energy. Acooling source 50 may be, for example, cold water (e.g. from artesianwells, glacial water or the ocean).

FIG. 3 illustrates the principle for a gas hydrate plant and thecomponents necessary for the process. The plant illustrated here usesmethane 1 and propane 2 as gases for the formation of gas hydrate. Thegases 1, 2 are blended in a mixer 3 and fed through a line 4 to areactor 21 for gas hydrate formation. Reactor 21 must be cooled by anexternal cooling source 50 since the reaction is exothermic. Further,water is fed to reactor 21 through line 8 for formation of gas hydrateand to form a mass of water and gas hydrate 31. Water from watercontainer 5 must be pre-processed, according to its quality, to removedisturbing impurities and is therefore first fed via line 6 to the watertreatment unit 7 and then conducted via line 8 into reactor 21. The mass31 formed in reactor 21 is fed into one or more reactors 20 for gashydrate decomposition. Here the gas hydrate is split and the mixture ofwater, gas and aqueous vapor 40 thus formed is fed into a separator 22,where the water is removed while the dry gas 41 is fed to a receiver 23for compressed gas. From here the gas 42 is conducted into a gas heater24. The heated gas 43 is fed into a turbine 10 as shown in FIG. 3 orinto an engine, for example a piston engine. Turbine 10 may, forexample, be connected to a generator 11. When the gas has emitted itsexcess energy to turbine 10, it is fed via line 30 back to reactor 21for gas hydrate formation. Thus, the consumption of methane 1 andpropane 2 will be limited to the start-up of the operation andreplacement of loss to the surroundings. Similarly, the water that isseparated out in separator 22 may be recycled in reactor 21 for gashydrate formation. Gas heater 24 and gas hydrate decomposition reactor20 are heated by means of the external heat source 51 described above.The heat is conducted to decomposition reactor 20 and the gas heater 24via lines 52 and 53, respectively.

In most cases hydrates are formed from hydrocarbon gas mixtures in apressure range of 0.5-50 MPa and at temperatures in the range of 273-303K. The composition of the gas can be adapted to the temperature of theheat source/cooling source that is used. It is advantageous to use gasmixtures that form gas hydrates at temperatures above 0° C. and lowpressure.

For a mixture of 85 mole-% of methane and 15 mole-% of propane. Based onthe following data it is possible to calculate the energy balance for aprocess that uses such a mixture:

-   μ_(g)=20.25—the molecular mass of the gas mixture;-   n=9.42—average number of water molecules in the hydrate;-   μ_(gh)=189.9—molecular mass of the hydrate;-   R=410.59 J/kgK—gas constant value for the gas mixture;-   ρ_(g)=0.91 kg/m³—density of the gas mixture;-   ρ_(gh)=893.9 kg/m³—density of the gas hydrate:-   T_(f)=280.15 K—gas hydrate formation temperature;-   P_(f)=0.88 MPa—gas hydrate formation pressure;-   ΔH_(f)=438.6 kJ/kg—gas hydrate formation energy;-   T_(f1)=270.15 K—water temperature at the entry to the gas hydrate    formation reactor at 0.88 MPa;-   T_(f2)=280.15 K—water temperature at the exit from the gas hydrate    formation reactor;-   T_(d)=299.15 K—gas hydrate decomposition temperature;-   P_(d)=29.28 MPa—gas hydrate decomposition pressure;-   ΔH_(d)=373.7 kJ/kg—gas hydrate decomposition energy at T=T_(d) and    P=P_(d);-   T_(t)=363.15 K—external water temperature at the entry to the heat    exchanger;-   T₁=363.15 K—gas temperature at the entry to the turbine;-   P₁=29.28 MPa—gas pressure at the entry to the turbine;-   C_(Pg)=2400 J/kgK—average thermal capacity for the gas mixture;-   C_(P1)=4200 kJ/kgK—average thermal capacity for water in the    temperature range of 280-363 K;-   C_(P2)=4199 kJ/kgK—average thermal capacity in the temperature range    of 270-280 K;-   C_(P3)=4100 kJ/kgK—water thermal capacity at the pressure of 29.28    MPa;-   C_(Pgh)=3942 kJ/kgK—gas hydrate thermal capacity at the pressure of    29.28 MPa;-   C_(Vg)=1989.4 kJ/kgK—gas mixture thermal capacity at a constant    volume.-   Amount of gas in 1 kg of gas hydrate=0.107 kg.-   Volume ratio of gas hydrate and water in the mass=1:1.

The calculation is done under the assumption that we obtain 1 kg of gasmixture (m_(g)=1 kg). The energy balance is the difference between theenergy brought into the system by hot water and the energy spent for gashydrate decomposition, gas heating and engine/turbine work.

To obtain 1 kg of gas it is necessary to decompose 9.35 kg of gashydrate, with the mass being preliminarily heated up from 280.15 K to299.15 K. The energy consumption is:E _(d) =C _(P3) ×m _(w) ×ΔT+C _(Pgh) ×m _(gh) ×ΔT+m _(gh) ×ΔH_(d)=4973.4 kJ.where the gas hydrate mass m_(gh)=9.35 kg and the water mass m_(w)=10kg.

The energy required to heat the gas from 299.15 to 363.15 K before it isfed into the turbine:E _(h) =C _(Pg) ×ΔT×m _(g)=153 kJ

Total consumption of energy from the hot water source: 5126 kJ.

Energy released in reactor during the formation of gas hydrate from 1 kgof gas:E _(f) =m _(gh) ×ΔH _(f)=4101 kJ

To obtain energy for decomposition of gas hydrate and heating of the gasit is required to have 19 kg of water at a temperature of 363.15 K,which is passed through one or more heat exchangers.

The energy released in the hydrate formation reactor goes partially forheating of the mass from 270 to 280 K (778 kJ), and the other part (3307kJ) is removed by cold (277 K) water. To cool the reactor down to 280 Kit is necessary for 263 kg of water to pass through the heat-exchangesystem.

The energy of 1 kg of gas may be found by the following formula:E ₁ =x ⁻¹ RT ₁{1−[P ₂ /P ₁]^(x)}=393.5 kJ.where x=(k−1)/k. k=C_(Pg)/C_(Vg)=1.206 and the gas pressure at the exitfrom the turbine P₂=P_(f)=0.88 MPa.

The efficiency of the process is the ratio between the gas energy andthe total consumption of energy from hot water, since it is only waterthat takes part in the work:η=(393.5/5126)×100%=7.7%

The integrated efficiency of the whole process, taking into account theenergy loss for cooling of the gas hydrate formation reactor, is:η=(393.5/8433)×100%=4.7%

The specific water consumption will be the following:

-   Hot water=48.3 kg/MJ-   Cold water=667.8 kg/MJ

The efficiency of the process naturally depends on the hot water orother heat carrier temperature.

In addition to the gas hydrates formed from hydrocarbons or a mixturethereof, as described herein, a number of other gases may be used insimilar processes. Such gases are, for example, rare gases, CO₂, otherhydrocarbon gases, Freon, nitrogen, and many others.

Also, a process similar to the one described in Example 2 may beemployed for the utilization of metal hydrides, for example MgH₂ asactuating agent. Magnesium hydride is formed from magnesium andtransition metal alloys at temperatures of 420-450 K and a pressure of1-5 MPa. The reaction is reversible. Released hydrogen is fed into aturbine or into a cylinder of an engine. A plant of this typeconsequently requires a storage tank for hydrogen.

EXAMPLE 3

Catalytic Dissociation of a 70-80% Solution of Hydrogen Peroxide

On FIG. 4 is shown an outline of a possible embodiment of a power sourcedriven by dissociation of hydrogen peroxide. The plant comprises a line40 for the injection of a solution or vapor form of H₂O₂ from anH₂O₂-reservoir 22 into a reaction chamber of a turbine 10 or an engine,in which a catalyst is placed. To turbine 10 there may be connected agenerator 11. H₂O₂ dissociates by the following reaction:H₂O₂→H₂O+½O₂+149.8 kJ

The volume of the resulting vapor and the oxygen is approximately 6000times greater than the volume of the injected H₂O₂, and the temperaturerises to 973-1023 K. When a turbine 10 is used, the reaction chamber maybe separated from it (not shown) and the mixture must consequently beconducted into turbine 10. The waste gas 30 from the turbine/engine isfed into a regeneration reactor 20 containing BaO₂, where CO₂ is added.Regeneration of H₂O₂ and BaO₂ proceeds according to the followingreactions:BaO₂+CO₂+H₂O→BaCO₃+H₂O₂BaCO₃→BaO+CO₂BaO+½O₂→BaO₂

Hydrogen peroxide is extracted by water and is led out of reactor 20 viapipeline 42 to a distillation column 21, where the hydrogen peroxide isconcentrated for subsequent use as an actuating fluid and is conductedvia line 41 to reservoir 22. The residual heat from exhaust gas 30 canbe used to carry out the distillation. Connected to reactor 20 is adevice 23 for regeneration of BaO₂. Regenerated BaO₂ is conducted byline 24 to a receiver for BaO₂, and from here a line 25 leads back toreactor 20, as needed.

BaO₂ is also regenerated according to the reactions above. The formationof hydrogen peroxide through the use of barium oxide and theregeneration thereof are known, inter alia, from DE 179771 and DE460030, as given by Walter C. Schumb et al., “Hydrogen Peroxide”,Reinhold Publishing Corp., New York, 1955. It is entirely possible touse other compounds to re-form hydrogen peroxide and to regenerate thesein a similar manner, for example 2-alkylanthrahydroquinone; see DE2228949, U.S. Pat. No. 2,966,397, DE 355866 and DE 179826.

The process exemplified herein theoretically uses only water and oxygenthat are supplied via lines 26 and 28 from the oxygen and water tank,respectively. In practice there will also be some consumption of carbondioxide, since CO₂ is dissolved in the water that is evaporated, and CO₂is supplied via line 27 from the CO₂ tank. The supplying of oxygen canbe accomplished by bringing in atmospheric air.

Energy Balance of the Process:

The calculation is based on a 70% solution of H₂O₂. The energy that isemitted includes, first, the energy from the catalytic dissociation ofH₂O₂, which is equal to 2785.4 kJ/kg according to V. S. Stepanov,“Chemical energy and exergy of substances”, Novosibirsk, Nauka, 1990,page 163 ff; and secondly, the energy from the catalytic exothermicreaction on the formation of BaO₂ in the solution, which is equal to1623 kJ/kg. The energy consumption consists of energy expended for workof the engine/turbine and the distillation column. The calculation isdone for 1 kg H₂O₂. The following data are used as a basis:

-   H₂O₂ concentration in the regeneration reactor=25%;-   H₂O₂ yield=90% of the theoretical quantity;-   C_(P1)=4200 J/kgK—water thermal capacity;-   C_(P2)=2630 J/kgK—H₂O₂ thermal capacity;-   C_(P3)=2344 J/kgK—thermal capacity of the gas mixture at 1100 K;-   C_(V)=1868.6 J/kgK—thermal capacity of the gas mixture at a constant    volume;-   R=475.4 J/kgK—gas constant for the gas mixture:-   T=1100 K—gas mixture temperature at the beginning of the process;-   k=C_(P3)/C_(V)=1.254;-   μ=17.488—gas mixture molecular mass;-   ΔH_(evap)=2258 kJ/kg—water evaporation energy at 333 K;-   E_(n)=4430 kJ/kg—energy consumed in concentrating H₂O₂ to 70%;

There is required 0.37 kg H₂O, 0.33 kg O₂ and 0.9 kg CO₂ for theproduction of 1 kg of a 70% solution of H₂O₂. The amount of BaO₂ thattakes part in the reaction is 3.44 kg, and the amount of energy releasedduring BaO₂ formation is 5583 kJ. The remaining 1153 kJ is used to heatup the H₂O₂ solution before it is fed into the reaction chamber of aturbine/engine and for heating the equipment. The energy from the H₂O₂dissociation is equal to 1546.5 kJ. The process efficiency η=56.2%.

EXAMPLE 4

Utilization of Thermal Process in Formation of Methane from CarbonMonoxide and Hydrogen

On FIG. 5 is shown an outline of a plant adapted to an embodiment of themethod according to the invention, where the actuating fluid is carbonmonoxide and hydrogen that are converted to methane and water. Such aplant could preferably be built in the proximity of a nuclear powerplant or another facility with high-temperature gas-cooled reactors. Theheat from these reactors is used for methane conversion. In thisexample, methane is used, but it is entirely possible to utilize otherhydrocarbon gases in similar processes. The methane is convertedtogether with water in a layer of boiling catalyst in a reactor 20heated by the external heat source 50. Through this reaction there areformed mainly carbon monoxide, CO and hydrogen, H₂. These gases 40 areconducted into a reaction chamber 21 where the following catalyticexothermic reaction takes place:CO+3H₂→CH₄+H₂O+206.4 kJ

By this reaction 28 g CO and 6 g H₂ are converted to 16 g CH₄ and 18 gwater vapor. When the methane-steam mixture leaves reaction chamber 21,it has a temperature of 900 K and a pressure of 5 MPa. This hot gasmixture is conducted via line 41 into a turbine 10 as actuating fluid.The turbine may be connected to a generator 11. The gas 30 leavingturbine 10 is fed into reactor 20 and is converted again. The tanks ofCO and H₂ shown in FIG. 5 are used to start-up the system, while oxygenand methane are used to cover any possible loss.

The optimal H₂O to CH₄ ratio is 3-4:1 at a conversion level of 0.99, ifthe process is carried out at an entry pressure of 3-5 MPa and atemperature of 1100 K. More details concerning this are described in V.A. Legasov et al., “Nuclear-hydrogen power engineering and technology,”Moscow, Atomisdat, 1978, pages 11-36.

Energy Balance of the Process:

The amount of energy released during the catalytic reaction between COand H₂ is equal to 206.4 kJ/mole.

-   T=900 K—starting temperature for the process;-   P₁=5 MPa—starting pressure for the process;-   P₂=0.11 MPa—ending pressure for the process;-   μ=17.03—molecular mass of the gas mixture;-   R=488.2 J/kg—gas constant;-   C_(P1)=69.14 J/moleK—thermal capacity of CH₄ at 900 K;-   C_(P2)40.26 J/moleK—thermal capacity of H₂O at 900 K;-   C_(P)=53.83 J/moleK—thermal capacity of the gas mixture at a    constant pressure;-   C_(V)=2672.7 J/kgK—thermal capacity of the gas mixture at a constant    volume;-   k=C_(P)/C_(V)=1.183;-   ΔH=12120 kJ/kg—the reaction energy;

The work carried out by 1 kg of gas mixture:

-   E=x⁻¹ RT [1−[P₂/P₁]^(x)]=1270 kJ, where x=(k−1)/k

The process efficiency η=(1272.7/12120)×100%=10.48%.

There are other ways of realizing the utilization of CO and H2 asactuating fluids. The choice of method depends on the availability ofnatural or industrial resources in the region where the plant is to beinstalled.

The difference between the method according to the invention and thestandard method of utilizing hydrocarbons is that, in addition to usingthe reaction energy, the reaction products are also used as actuatingfluid for turbine operation. In a conventional method the reactionenergy is used to heat up water in order to make steam that is used asan actuating fluid in a turbine.

The method exemplified herein may also be installed near a chemicalplant that utilizes the conversion products for the purpose ofsynthesis. The methane produced may in that case be used wholly orpartially as raw material instead of being recycled.

1. A method for production of mechanical energy from an energy producingunit, characterized in that the energy is supplied by any cyclicthermo-chemical process, excluding oxidation processes, comprisingpassing an actuating fluid through the energy producing unit, where theactuating fluid before entering or within the unit undergoes athermo-chemical reaction causing a direct or indirect volume expansionthereby producing mechanical energy, and converting an output fluid fromthe energy producing unit into the actuating fluid.
 2. The methodaccording to claim 1, characterized in that the actuating fluid consistsof any gas or a gas mixture or a gas-vapour mixture.
 3. The methodaccording to claim 2, characterized in that the actuating fluid isactivated, finely-dispersed, partly dissociated water.
 4. The methodaccording to claim 3, characterized in that the output fluid, afterbeing cooled turns consecutively into steam and then into source waterfor regenerating the actuating fluid.
 5. The method according to claim1, characterized in that the actuating fluid is gas hydrates, metalhydrides, fixed gases or low-boiling liquids vapour.
 6. The methodaccording to claim 5, characterized in that said thermo-chemicalreaction converts the actuating fluid to consist of gases obtained bygas hydrate melting, by metal hydride decomposition or by desorption. 7.The method according to claim 1, characterized in that the energy issupplied by hydrogen peroxide or its water solution.
 8. The methodaccording to claim 7, characterized in that hydrogen peroxide is fedinto the energy producing unit, said thermo-chemical reaction is acatalytic decomposition of hydrogen peroxide into a mixture of gases H₂Oand O₂, and that the output fluid is converted into hydrogen peroxide tobe fed to said unit.
 9. The method according to claim 8, characterizedin that it further comprises reacting the output fluid with BaO₂ and CO₂producing Hydrogen peroxide and BaCO₃, and converting thus formed BaCO₃to BaO₂.
 10. The method according to claim 1, characterized in that theenergy is supplied by a mixture of H₂ and CO.
 11. The method accordingto claim 10, characterized in that said thermo-chemical reactioncomprises bringing the mixture of H₂ and CO in contact with a catalystthat exothermally converts H₂ and CO into a mixture of CH₄ and watervapour, and that the output fluid is converted into H₂ and CO under theinfluence of external or internal heat source.
 12. A method forproduction of mechanical energy from an energy producing unit,characterized by comprising creating a hot actuating fluid by addingwater that has been at least partly dissociated and ionized to a gas orgas mixture, letting the actuating fluid expand, cool and the ionsrecombine in said unit, thereby creating said mechanical energy, andcondensing an output fluid from said unit thereby producing water.
 13. Amethod for production of mechanical energy from an energy producing unit(10), characterized by feeding a fluid (31) comprising a gas hydrate,metal hydride or fixed gases to a decomposition reactor (20), where thefluid (31) is decomposed by means of dissipated heat energy, conductingthe decomposed fluid to a separator (22), where gas (41) is separatedfrom the fluid, optionally heating the gas (42), conducting theoptionally heated gas into the energy producing unit (10), andconducting the output fluid (30) from the energy producing unit (10) toa reactor (21), where the output fluid (30) is converted to gas hydrate,metal hydride or fixed gas, respectively.
 14. A method for production ofmechanical energy from an energy producing unit (10), characterized byfeeding a solution of hydrogen peroxide or hydrogen peroxide steam (40)to the energy producing unit (10), where the hydrogen peroxide is splitinto oxygen and water steam in the presence of a catalyst, which causesa volume increase and a temperature rise that drives the energyproducing unit (10), and conducting the oxygen and water (30) from theunit (10) to a reactor (20) where the hydrogen peroxide is regenerated.15. A method according to claim 14, characterized in that the hydrogenperoxide is regenerated by reaction with BaO₂ and CO₂, and the BaCO₃thus formed is converted to BaO₂.
 16. A method for production ofmechanical energy from an energy producing unit (10), characterized byfeeding an input fluid (40) comprising H₂ and CO to a reaction chamber(21) comprising a catalyst for formation of methane and water,conducting the fluid (41) comprising methane and water from the reactionchamber (21) to the energy producing unit (10), where the fluid (41)drives the energy producing unit (10), and conducting an output fluid(30) from the energy producing unit (10) on to a reactor (20), where theoutput fluid is converted into an input fluid (40).
 17. A plant forproduction of mechanical energy, comprising an energy producing unit(10) equipped with an inlet for an input fluid (40) and an outlet for anoutput fluid (30), characterized by further comprising an actuatingfluid present in the energy producing unit, a first chemical reactionchamber (20) for a non-oxidative thermo-chemical reaction having aninlet in fluid connection with the outlet from said unit and an outletin fluid connection with the inlet to said unit, where said actuatingfluid is regenerated in the first chemical reaction chamber from theoutput fluid (30) and where said unit comprises a second chemicalreaction chamber for releasing energy from the actuating fluid.